14 research outputs found

    9-PAHSA displays a weak anti-inflammatory potential mediated by specific antagonism of chemokine G protein-coupled receptors

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    Introduction: 9-PAHSA belongs to a class of endogenous mammalian bioactive lipids, fatty acid esters of hydroxy fatty acids (FAHFA), that are present in circulation at nanomolar concentrations in mice and humans. Published preclinical data suggest beneficial effects of 9-PAHSA treatment on glucose metabolism as well as modulation of immune function. However, receptor molecules with high affinity towards these lipids have not been identified so far.Methods: In a broad screen of a panel of G protein-coupled receptors (GPCRs) we discovered that 9-PAHSA displays antagonist activity with an IC50 in the micromolar range on selected chemokine receptors, namely, CCR6, CCR7, CXCR4, and CXCR5. The potential immunomodulatory activities in a human cellular model of innate immunity were then investigated.Results and discussion: In our in vitro experiments, a weak anti-inflammatory potential for high concentrations of 9-PAHSA (10–100 ”M) could be detected, as treatment reduced the LPS-induced secretion of certain chemokines, such as CXCL10, MIP-1 beta and MCP. Regarding metabolic effects, we re-investigated 9-PAHSA on glucose metabolism and insulin sensitivity in vitro and in mice confirming conclusions from our earlier study that FAHFAs lack glucoregulatory activity following an acute treatment. In conclusion, the specific interactions with a subset of chemokine receptors may contribute to weak anti-inflammatory properties of 9-PAHSA, but further studies are needed to confirm its in anti-inflammatory potential in vivo

    High-throughput mediation analysis of human proteome and metabolome identifies mediators of post-bariatric surgical diabetes control

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    To improve the power of mediation in high-throughput studies, here we introduce High-throughput mediation analysis (Hitman), which accounts for direction of mediation and applies empirical Bayesian linear modeling. We apply Hitman in a retrospective, exploratory analysis of the SLIMM-T2D clinical trial in which participants with type 2 diabetes were randomized to Roux-en-Y gastric bypass (RYGB) or nonsurgical diabetes/weight management, and fasting plasma proteome and metabolome were assayed up to 3 years. RYGB caused greater improvement in HbA1c, which was mediated by growth hormone receptor (GHR). GHR’s mediation is more significant than clinical mediators, including BMI. GHR decreases at 3 months postoperatively alongside increased insulin-like growth factor binding proteins IGFBP1/BP2; plasma GH increased at 1 year. Experimental validation indicates (1) hepatic GHR expression decreases in post-bariatric rats; (2) GHR knockdown in primary hepatocytes decreases gluconeogenic gene expression and glucose production. Thus, RYGB may induce resistance to diabetogenic effects of GH signaling

    A GLP-1R/GCGR dual agonist exhibits differential effects on metabolic control versus a single GLP-1R agonist by activation of BAT and browning in diet-induced obese mice

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    Resumen del trabajo presentado al 13th International Symposium on Insulin Receptor and Insulin Action, celebrado en Niza (Francia) del 20 al 22 de abril de 2017.[Question]: Brown adipose tissue (BAT), a specialized fat that dissipates energy to produce heat, plays an important role in the regulation of energy balance. We designed a pharmacological intervention protocol with a GLP-1R agonist and GLP-1R/ GCGR dual agonist to investigate their effects in preventing diet-induced obesity in m ice by enhancing BAT activation, browning and insulin signaling in differentiated brown adipocytes (BA). [Methods]: 8 week-old male C57Bl/6 mice were fed chow or high fat diet (HFD) for 10 weeks. HFD-fed mice were subsequently injected (s.c. every 2 days) vehicle or a GLP-1R agonist (10 nmol/kg) or G49, a GLP-1R/GCGR dual agonist (4.4 mg/kg). Parameters assessing obesity, glucose homeostasis, b-cell function, BAT activation and browning were analyzed following treatment for 3-6 weeks. lnsulin signaling was assayed in differentiated BA. [Results]: Following 3 weeks of treatment, body weight loss was greater in m ice injected G49 compared to those injected GLP-1R agonist. PET analysis revealed cold-induced activation of BAT by both drug treatments, but the effect was higher in G49-treated group. These differential effects were maintained following 6 weeks of treatment, at which time adiposity and macrophage inftltration of eWAT were reduced and UCP1 immunostaining in BAT and iWAT was increased. Also, the effects of G49 in inducing mRNA levels of BAT activation markers and browning in iWAT and eWAT were higher in m ice injected G49. A stronger decrease in plasma glucose and insulin was detected in G49-treated animals versus those receiving GLP-1 R agonist in parallel with improvement of islet morphology. The higher efftcacy of G49 was tested in differentiated BA by its effect in counteracting the impairment in insulin signaling induced by pro-inflammatory cytokines. [Conclusions]: Our results strongly suggest a novel role of an oxyntomodulin-like dual acting GLP-1R/GCGR agonist in reducing obesity and improve insulin sensitivity by increasing energy expenditure due to its effects in BAT and beta-cell function.Peer Reviewe

    Differential efficacy of a GLP-1R/GCGR dual agonist versus a single GLP-1R agonist in diet-induced obesity in mice

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    Trabajo presentado al CIBERDEM 8th Annual Meeting, celebrado en Barcelona (España) del 17 al 19 de mayo de 2017.Peer Reviewe

    DataSheet1_9-PAHSA displays a weak anti-inflammatory potential mediated by specific antagonism of chemokine G protein-coupled receptors.docx

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    Introduction: 9-PAHSA belongs to a class of endogenous mammalian bioactive lipids, fatty acid esters of hydroxy fatty acids (FAHFA), that are present in circulation at nanomolar concentrations in mice and humans. Published preclinical data suggest beneficial effects of 9-PAHSA treatment on glucose metabolism as well as modulation of immune function. However, receptor molecules with high affinity towards these lipids have not been identified so far.Methods: In a broad screen of a panel of G protein-coupled receptors (GPCRs) we discovered that 9-PAHSA displays antagonist activity with an IC50 in the micromolar range on selected chemokine receptors, namely, CCR6, CCR7, CXCR4, and CXCR5. The potential immunomodulatory activities in a human cellular model of innate immunity were then investigated.Results and discussion: In our in vitro experiments, a weak anti-inflammatory potential for high concentrations of 9-PAHSA (10–100 ”M) could be detected, as treatment reduced the LPS-induced secretion of certain chemokines, such as CXCL10, MIP-1 beta and MCP. Regarding metabolic effects, we re-investigated 9-PAHSA on glucose metabolism and insulin sensitivity in vitro and in mice confirming conclusions from our earlier study that FAHFAs lack glucoregulatory activity following an acute treatment. In conclusion, the specific interactions with a subset of chemokine receptors may contribute to weak anti-inflammatory properties of 9-PAHSA, but further studies are needed to confirm its in anti-inflammatory potential in vivo.</p

    Dual Glucagon-like Peptide 1 (GLP-1)/Glucagon Receptor Agonists Specifically Optimized for Multidose Formulations

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    Novel peptidic dual agonists of the glucagon-like peptide 1 (GLP-1) and glucagon receptor are reported to have enhanced efficacy over pure GLP-1 receptor agonists with regard to treatment of obesity and diabetes. We describe novel exendin-4 based dual agonists designed with an activity ratio favoring the GLP-1 versus the glucagon receptor. As result of an iterative optimization procedure that included molecular modeling, structural biological studies (X-ray, NMR), peptide design and synthesis, experimental activity, and solubility profiling, a candidate molecule was identified. Novel SAR points are reported that allowed us to fine-tune the desired receptor activity ratio and increased solubility in the presence of antimicrobial preservatives, findings that can be of general applicability for any peptide discovery project. The peptide was evaluated in chronic <i>in vivo</i> studies in obese diabetic monkeys as translational model for the human situation and demonstrated favorable blood glucose and body weight lowering effects
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